Continuous experiment was performed on a industrial scale for the production of sponge iron by using tunnel kiln furnace. Crushed ores were classified into fwo parts of which one consists of the size 10-40min, and another of the size under 10mm. The latter were crushed again up to all under 30mesh. Ores of the size 10-40mm were mixed with fine coke and put in chamotte containers. Fine are was mixed with Boilable amount of carburising medium. The mixture was put in a phamotte container in such way as not to mix with the reducing coke. These containers were placed on a car, which ran through the kiln. The max. temp of the kiln was kept at about 1300°C. The seduced products were solid mass of sp. gr. about B.G. The sp. gr. of 7 may be obtained, if desired, by suitably charging conditions. According to this experiment it was shown that the sponge iron might be easily produced by tunnel kiln.

View full abstract

The authors explained the practical vilue of the representative kinds of sponge iron and luppe from different sources which were used as substitute for the scrap.

View full abstract

The author has made some experiment of making commercial ingots at a certain factory for more than ten years since Taisho-10(1921), in view of lightening the segregation inside of most heavy-sectioned ingots. The first experiment of the method of water-cooling moulds had proved to be unsuccessful for the heavy-sectioned ingots.
Then the author devised a mould-rotating apparatus, with which various methcds of centrifugal casting were experimented; the result being as follows:-
The continuous +otation in the same direction from the beginning of casting to the point of soli dification indicated no influence on the mode of segregation. However, the reversal or intermittent rotation proved remarkably to lessen the ring gohst zone at the top of ingots. Therefore, it was known that such kind of rotation may accelerate the tendency of-impurities to be driven into the core from outside or to float upwards from below during the solidification of ingots.

View full abstract

The simplest stepped quenching is conducted on the following way: water quenching -lifting in air or water quenching-lifting in air-second water quenching. In case where the simplest stepped quenching was made on carbon steel samples of cylindrical form, the change of the internal temperature within the sample was obtained both from the calculation of heat conductivity and from the experiment, and the value of constants in the calculation was determined so as to coincide in both ways. Since the calculation formulae and constants thus obtained was applied to the stepped quenching of specimens of different dimensions and the result coincident with the experimental value obtained, it was presumed that the thermal change within the steel shape might be worked out only by calculation without actual measurement when heavy sections was quenched in the stepped method.
Moreover, the change of structural and hardness distribution in the section of specimens was experimentally studied and the relationship between both distributions was obtained, where the time interval of each stage of the stepped quenching was varied diversely.
Finally, it was shown that special structural and hardness distributions occurred in the stepped quenching of the carbon steel specimen may be rationally explained from the isothermal (cooling) transformation curve. It was suggested that, when the isothermal. transformation curve was obtained beforehand, the internal thermal change as well as the structural and hardness distribution in the steel shape may be derived generally only by utilizing the calculating formulae.

View full abstract

Als die Voraussetzung der Spannungsmessung an der versepiedenen warmebehandelten Sonderstahle versuchte der Verfasser die folgende Experiment An der Oherflache des innerhalb der Elastizitatsgrenze gebogenen Prufsttickes warde Spannung rontgenographisch gemess des innerhalb der Elastizitatsgrenze gebogenen Prufsttickes warde Spannung rontgenographisch gemess im Versuch I gewahlt und die schief beleuchtete im Versuch II Jeder so rontgenographisch gemessene Spannungswert wurde mit dem sus der gleichzeitig gemessenen Biegung berechneten Wert vergleiclat. Aus diesen Versuche kann man erkennen, dass der mittlere quadratische Felder von der Aufnahme weise abhangt und es den kleinsten (±2.2kg/mm²) bei der sehief beleuchteten Rucketrahlaufnahme[an der (ψ+η+)-Seite beiψ=45°] nimmt, den Mittieren Wert (±2.7kg/mm²) bei der senkrecht konzentrisch beleuchteten. und den groseten Wert (±3.5kg/mm²) bei der senkrecht beleuchteten.

View full abstract

Indem die leicht zu bedienende Kohlespiralofen von einfachen Ballart Indem die leicht zu bedienende Kohlespiralofen von einfachen Ballart Kohlespiralofen, welche aus einer im Glasbehalter eingeschlossenen kleinen Kohlespiralofen aus Molybdanbleche bestebt, wird durch die elektrische Strom von 100 V, 20 A auf 1700°C erhitzt. Also ist die elektrische Ausrustung einfach und die Entgasungsdauer kurz. Binnen zwei Stunden wird der Druck von 0.0005mm Hg erreicht. Da die verdathpften Metalle such durch die Saure gewaschep werden, sind die genauen Analysenergebnisse immer erhalten. Durch diese Apparatur wurde der Einfluss von Mangan und Silizium auf die Analysenergebnisse der verdampften Metalle unterstacht. Beim Mangangehalt bis ztr 1.5% und Siliziumgehalt bis 1.5% sind Mangan und Silizium von keiner Einfluss auf die Analysenergebnisse des Sauerstoffes. Mangan und Silizium aber haben fast keinen Einfluss auf die Analysenergebnisse des Stickstoffes.

View full abstract